FILE- In this July 6, 2017, file photo, former Sheriff Joe Arpaio leaves the federal courthouse in Phoenix, Ariz. Jurors at a malicious-prosecution trial against Arpaio were told the lawman brought a trumped-up criminal case against one of Sen. Jeff Flake's sons to garner publicity for himself. (AP Photo/Angie Wang, File)

PHOENIX (AP) — Former Arizona sheriff Joe Arpaio has announced he plans to run for the U.S. Senate seat now held by Jeff Flake.

The 85-year-old Arpaio is a Republican and close ally of President Donald Trump.

Arpaio tweeted Tuesday he seeking the post to support Trump’s agenda “in his mission to Make America Great Again.”

Arpaio was spared a possible jail sentence last year when Trump pardoned his conviction for disobeying a judge’s order in an immigration case.

He flirted with the idea running for Arizona governor five times but decided against doing so each time.

Arpaio says in a fundraising email that he filed paperwork Tuesday for the Senate run.

The Republican Flake has been critical of Trump and announced last year that he would not seek another term.